Process of producing patterns for castings, &amp;c.



v M. 'KELSBYS PROCESS OF PRODUCING PATTERNS FOBGASTINGS, 6w.

1 APPLICATION FILED sn'rur. 1, 1910. 1 037 489, Q Patented Sept, 3, 1912.

I I I 1 I 1 I 1 teeth because the removal of the porcelain 7 merit of a large amount of capital would be required owing to the precious rnetalcom been wasted in trimming down stock "ternstothedesired sizeand sl a 38nd t erej has also been difliculty in entistry, m

MARK KELSEY, OF LOS ANGELES, CALIFORNIA.

PROCESS OF PRODUCING PATTERNS FOR- CASTINGS, &0.

' Specification of Letters 2mm.

Patented Sept. 3, 1912.

Application filed September 1, 1910. Serial No. 580,131.

To all whom it may concern Be it known that I, Mam: KEnsEY, a citizen of the United States, residing at Los Angeles, California, have invented a new 5 and useful Process of Producing Patterns for Castings, &c., of which the following is a specification. I

Among the objects of this invention are t0 produce a combustible pattern of sufii- 10 cient stability to be transported and handled as a stock article without injury; to provide for economically manufacturing sample patterns in such large numbers that the trade canbe, without too greatan expense, suppliedwith a sufficient variety of stock forms and sizes to accurately designate to manufacturers any cast article that the consumer may desire; to provide a more perfect method, applicable especially to dentistry, for casting the attachments of porcelain teeth and orcelain facings, and for forming metallic hmmies in bridgework. Hitherto it has been impossible to secure erfect wax patterns to make one-piece ackings for the attachment of porcelain preparatory to casting distorts the wax patterns. Another ifliculty heretofore encountered has e61 the fact that backing? or attachments or the porcelain teethave tendency to burn while casting or to oxidize suflicientlv to prevent perfect union; and

form as to readily handled and trimmed preparatory to casting. Other difficulties are that in order to make a suflicient number'of atterns to supply a great variety of forms or jewelers and dentists. the investtained in the stock forms. Furthermore, a large amount of precious metal has hithertto been made of a metal which either shows a which applies to. all methods heretofore employedin dentistry is that atterns are not made in'such a I the attachmentshown in joining the two ieces of metal usedin the attachments or ackings to porcelain facings and teeth. Moreover, the present methods of casting a body of new metal to a metallic base, in dentistry, have been found uncertain on account of more .or'less oxidation of the metallic base.

One Way in which this invention over-' comes the greater number of the foregoing difficulties is by providing a method of forming the backing or attachment used by dentists and the castings used by jewelers, into one solid homogeneous piece of metal, and also avoiding all air spaces and waste of material.

Broadly considered this invention relates to a new article of manufacture consisting of a pattern made of a highly'combustible material of suflicient rigidit to permit the same to be transported and andled as may be necessary.

The invention further consists in a method I of constructi-n patterns for castings out of materials one of which is a plurality 0 highly combustible and yet possesses sufiicient rigidity to form a support upon which a more plastic exterior may be placed to' build to desired contour.

' Referring to the accompanying drawings,

which illustrate the invention as applie to dentistry and jewelry, Figure 1 is a vertical section of a tooth root and porcelain tooth showing therein the moldpattern. Fig. 2

completed pattern invested .t erein. 1 ig. 3

is a sectional view of a'moljl showin .the

is -a perspective of the foun' ation body or skeleton of the pattern. Fi 4 is a transverse section of a backin for a porcelain tooth illustrating the me iod of attaching said backing to a gold crown. Fig. 5is' a perspective of the backing piece shown in section-sin Fig.4. Fi 6 is-a -vertical -sec-.

tion of a mold containing the pattern for the backing piece of Fig} 5 together with i .4. Fi'.7isa plan view of a foundation ody to to the trade as a pattern for casting a ring. This view is artly sectioned in order to sold showa recess in the side thereofto be filled I with wax to su port the pattern on a spru'e. Fig. 8 is an ed ge view of the ring pattern shown in Fig. -7. Fig. 9 is a sectional view 'of a mold showingthe, ring pattern therein completed by fillin the cavity therein with wax, the 'sprue having been withdrawn.

Referring first to Figs. 7 apply the invention to t e setting ofporcelaiii crowns, first select a suitable porcelain tooth 1 and. grind in the usual manner to secure approximate fit to root 2, the root .being reamed to receive a pin. Then select when in place force slightly dampened porcelain tooth 1 over pattern projecting from root thus forcing wax partially out and leaving porcelain crown inproper position to form the wax portion 6 on flange 4. Then chill wax and remove porcelain tooth 1. Next remove completed pattern from tooth root and place upon the usual sprue (not shown) and invest in the usualway as in' a mold 5- containing investing material 5 employed in pressure casting where a disappearing pattern is used. Then heat the mold for the'sprue (not shown); Fig. 9 shows sufiicient-ly to remove the wax and skeleton by combustion and it is ready for use in forming the casting in the usual manner.

In order to apply the invention to attachments of porcelain facings to stationary fixtures in the mouth, select facing 7 of proper size and shape to fill space, grind to place, select backing 8 of celluloid or similar rigidcombustible material and trim to proper shape and size, fit to porcelain facing, put facing and backing together in place and join it to the abutment (in this case the gold crown 11) by means of a body of wax 12; Now remove facing 7, backing 8 and wax 12 together, from abutment 11. Then remove facing 7 from backing 8 and fix a sprue (not shown) into wax 12 and invest said wax and backing, thus supported,

in the usual manner. The investment may be made in a mold 13 containing investing material 14. Then clear the mold chamber by heating as already described.

The skeleton 3 and its flange 4: are provided with a roughened surface as shown" in Fig. 3 to cause the wax to adhere more firmly.

Celluloid is plastic when heated allowing it to be pressed into any-desired form, and therefore enables making of. skeleton patterns of any shape or size and in comparatively large quantities at small expense.

In'Fig. 7 is shown a ring pattern or foundation body 15 of celluloid, having'a recess filled with wax 16 to form attaching means the ring invested in a mold 17 containing investing material 18. The next step is to heat the mold sutficiently to destroy the pattern by combustion in order to makeroom for the casting. It will be seen that the foundation body for the ring has features in common with the foundation bodies of the first two forms described although a smaller amount of wax is required to form the completed pattern.

According to present methods it necessitates an enormous expenditure of capital to carry a sufiicient variety of forms and sizes of wedding rings and other stock rings to supply the demands of consumers. Without such an extensive stock, drawings must be made which do not exhibit the article as well as patterns. By using the patterns provided by this invention as hereinbefore last described, after the selection of the patmensions than said cavity, and forming the pattern by building upon said skeleton a plastic filler which is combustible or fusible.

2. The process of forming a pattern which consists in placing in position a rigid skele-. ton composed of a material removableby heating ;,,and forming the pattern by bu lding upon said skeleton a plastic addltion which is combustible or fusible.

' 3. The process of forming apattern which which is to be fille by a casting a skeleton .of. smaller dimensions than said cavity;

and building upon said skeleton a plastic filler to form the pattern.

4. The process of forming a pattern which consists in building a plastic addition externally upon and supporting the same by a celluloid backing member to form the pattern. I

5. The process of forming a pattern, which consists in applying to the exterior of a .fusible skeleton, a plastic addition of fusible material, and introducing the two into a cavity, to cause the plastic addition to take the form of said cavity, and thus produce the pattern.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses at Los Angeles, in the county of Los An'geles and State Of Cahfornia, this 27th dayof August, 1910.

MARK KELSEY.

Witnesses :1 p i i ALBERT H. MERRILL, LILLIA'N YoUNo. 

